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Otters back from the brink of extinction

Otter populations in the UK have made a remarkable comeback from the brink of extinction. According to the Guardian, their recovery is largely due to less polluted rivers resulting from UK bans on organochlorine pesticides (OCs) in the 1970s. Not only is the water safer for the otters, who are high up in the aquatic food chain, but also for their prey: fish populations have likewise recovered.

DDT was famously responsible for the collapse of raptor populations in the U.S., particularly the bald eagles, who are high on the terrestrial food chain. As studies and news reports from around the country attest, since EPA banned DDT in the U.S. in 1972, raptor species including eagles, peregrine falcons and hawks have made successful recoveries and their populations are once again stable in the wild.

OC pesticides like DDT have a history of laying waste to wildlife populations. This class of pesticides persists in the environment for decades, travelling on wind and water, and accumulating in the bodies of animals in increasingly higher concentrations as they move up the food chain—a phenomena called "bioaccumulation." As recently documented by Alaska Community Action on Toxics, these "POPs" are especially prevalent in the arctic, thousands of miles from where they were applied.

Many OC pesticides remain in use around the world. Endosulfan, for instance, is found as a residue throughout the U.S. food supply on cucumbers, green beans, tomatoes and more. In addition to persisting in the environment, low-dose endosulfan exposure is linked to endocrine disruption, delayed puberty and autism in humans. There is progress however. Endosulfan has been a focus of PAN campaigning for the last decade, and was just this year slated for a six-year phaseout by the EPA. Last week the technical review committee of the Stockholm Convention on Persistent Organic Pollutants moved endosulfan ahead toward a global phaseout. The final decision will be made in April 2011 at a meeting of all 172 countries that have signed onto the treaty.